1. Field of the Invention
The present invention relates generally to an apparatus and method for measuring the aim of vehicle headlamps; and, more specifically, for measuring the light intensity to check the aim of a vehicle headlamp.
2. Description of Related Art
Vehicle headlamps illuminate the roadway in front of a vehicle. Designed to project light over the roadway in a particular pattern headlamps must be aimed according to certain preset standards. Modern automotive vehicle manufacturers use a variety of headlamp designs that are placed on a variety of vehicles. Each headlamp design has a different aim specification and tolerance; therefore, each headlamp should be checked to ensure it meets proscribed standards. Typically, the headlamp manufacturer controls the headlamp pattern or optical prescription. Thus, the vehicle manufacturer properly aims the headlamp by aligning the headlamp on the vehicle.
One method of checking headlamp aim is to direct the headlamp at a screen assembly and compare the illumination pattern with a pre-established proper alignment pattern for a particular headlamp located on a specific vehicle. This comparison method requires a plurality of pre-established standards, one for each type of headlamp and vehicle. An additional problem with comparison type systems is that it is sometimes difficult to determine what part of the optical prescription is being compared. Comparison systems are often limited to detecting hot spots and not recording or analyzing data, specifically light intensity over the entire area of illumination. Accordingly, it is desirable to have an apparatus that can obtain and record objective data, including light intensity, for a multitude of headlamp types, styles and designs while at the same time having the flexibility and capability to aim and audit a variety of headlamps.